Fastener and art of producing same



Feb. 25, 1936. H. ROSENBERG 2,032,099

FASTENER AND ART OF PRODUCING SAME \IIIIIIIII 5 I I FIG. 7. HEYMANRUBENBjfij,

Patented Feb. 25, 1936 9 UNITED "STATES- PATENT OFFICE 2,032,099FASTENER AND ART OF PRQDUCING SAME v l ieyman Rosenberg, New York, N. Y.

Application March 3, 1932, Serial No. 596,637 8 Claims. (01. 10-161)This invention relates to improvements in that type of fastener whichhas come to be known as water-proof or leak-proof, and it has heretoforebeen proposed to prevent leakage between parts of a nail orlike'fastener and parts of a metal sheet penetrated by the fastener bythe provision of a lead or like soft metal head or cap or washer for thefastener.

In the previously proposed devices, however, in which a washer'ismounted on the shank of a nail beneath its head, or the head of a nailis encased in lead either cast or die-stamped, difiiculty has beenexperienced in the successful use for the purpose intended and asubstantial expense has been involved from the tendency of. the lead toform fissures and separate from contacted parts and from excessivequantities of lead required in such previously proposed devices.

It is the essential object of the present invention to materially reducethe expense of production and to eliminate the mentioned difficultiesand defects in operation.

In the previously proposed constructions in which a lead washer or alead casing for the head of a nail or like fastener was provided withthe object of rendering the joint between the head and the sheet metalengaged thereby moistureprcof, defective results have occurred fromcracking of. the lead or the curling of the lead to a cupped conditionand a failure of the lead, whether die-stamped, molded, or merelyapplied in the form of awasher, to sufficiently intimately engage thesurfaces of the nail to preclude moisture leakage between the lead andsuch surfaces.

A more detailed object of the present invention is the elimination ofthe possibility of leakage between a highly malleable area of materialand the main stock of the fastener.

With these and further objects in view as will hereinafter in partbecome apparent and in part be stated, the invention comprises certainnovel constructions, combinations, and arrangements of. parts assubsequently specified and claimed.

The invention also comprises certain novel steps and combinations ofsteps in the art of producing fasteners for rendering the same leakproofinexpensively and eifectively.

In the accompanying drawing,--

Figure 1 is a fragmentary, sectional elevation of a fastener blank welladapted for the practicing of the art and the production of the fastenerhead comprising the present invention.

Figure 2 is a similar view of the same in its completed condition.

Figures 3, 4, 5, and 6 are respectively views similar to Figure 2 ofslightly modified embodiments.

Figure 7 is a view similar to Figure 3 with the upper marginal coveringomitted.

It will be readily understood by those familiar with the art to whichthe present invention relates that cornices, metal roofing, metallic boxcoverings, and like weather-shedding coverings have heretofore beenanchored by various means, such as the driving of nails through parts ofthe metal cover sheet into wooden supports below and subsequentlysoldering the head of the nails to the penetrated sheet, and while thisusually makes a very acceptable anchorage and leak-proof joint, thenecessary hand operations are both laborious and expensive, and it,therefore, has been pro-posed to substitute lead or like soft .metal inloose form already applied to the fastener in the hope and expectationof causing such intimate contact incident to the pressure under whichthe fastener is applied as to preclude leak age. Such fasteners, ofcourse, have included the ordinary hammer-driven wire nails and likefasteners whether actually hammer-driven or otherwise stressed into thefinally seated position, and though the accompanying drawing illustratesthe invention as particularly applied to nails, drive screws, and woodscrews, it should be understood that the invention is as well applicableto the head of other fasteners however subjected to pressure for seatingpurposes in the finally anchored posit-ion.

Since much of the defects of previously proposed anchorage devicesutilizing an interposed soft metal between the fastener head and thesheet engaged have been due to lack of effective contact either betweenthe soft metal and the sheet or between the soft metal and the head orother engaged part of the fastener, and since such lack of effectivecontact has arisen either from the initial loose condition of the leadrelative to the head of the fastener or the loosening thereof from thefastener, as by splitting, cracking, or other defect developed underhammer blows or under differential contraction and expansion withclimatic temperature variations, the present invention includesprovision against possibility of any such defects.

In the practicing of the present improved art for the production of thepresent improved fastener. head, it is possible to employ a commercialnail, screw, or other well known fastener already in use or on themarket, but I prefer to utilize an especially shaped fastener headadapted particularly for enhancing the value of the present invention.To this end, and referring more particularly to Figures 1 and 2 of thedraw- 8, I indicates the shank of a fastener which ordinarily would beconsidered a nail but may be a wire or other fastener provided with ananchoring head 2. When the fastener Ii is a nail, the head 2 ispreferably provided with a bulbous enlargement 3 especially adapted toreceive hammer blows, but it will be readily understood that the bulbousenlargement 3 may be omitted. The head 2 may be of any of variousproportions and contours, 'but preferably is concavo-convex orumbrellashaped, and the peripheral portion of the headi. is preferablyprovided with a'circumferential rabbet d. The concave-convex: head fornails is known commercially, but I am unaware of any previous attempt,or suggestion to provide a rabbet corresponding to the rafebet 4'.

The head i, owing to its COIltOHlyDl'OVitif-IS an inner space 5 insuringeffective contact of peripheral portions of the head against the engaged1 sheet, and space 5 may either be ieft as a space or be filled withlead.

In the practicing of the art forming part of the present invention, thefastener l is of iron or other appropriate metal and is subjected to aninitial step of coating, as by applying zinc or lead, or otherappropriate metal, preferably by way of the electrolytic bath or the hotgal vanizing of metal. The coating must not be merely superficial butapplied in a -manner,-as

by hot galvanizing, to insure penetration of the pores of the metal ofthe fastener so as to be- I come commingled and interlocked with and inthe fiber of the metal of the fastener as by the flowing of molten metalinto the pores of the material of the fastener so as to approach acondition homogeneous therewith. Thus, there is provided in the materialof the fastener, about the engaged surface thereof, a mixed, mingled orblended area of lead or zinc or other soft metal with the iron or steelor other appropriate metal of the fastener. Of course, while the wholefastener i is usually thus coated, it should be understood that so faras the present invention is concerned, it is essential only that thecoating be applied to those portions of the fastener to be supplied withthe lead or. other soft metal cushion or covering.

As a matter of facility of procedure, the fastener with its head 2 thuscoated is preferably allowed to cool and is either dried in a dryingmachine or otherwise preceding the next step in the process. It is, ofcourse, possible to employ fasteners already on the market ifproperlygalvanized or otherwise satisfactorily coated so that the coatingincludes an area of softer metal mingled or blended with the hardermetal of the fastener.

The head 2 and particuiarly the parts thereof to receive the lead orlike soft metal pad or coating is then supplied with a flux preferablybyhaving the flux sprayed thereon, and then those parts of thehead 2to'receive the lead covering are dipped into a molten lead bath, removedtherefrom, and afforded an opportunity for draining. However coated, thehead is preferably revolved during the draining operation to afforduniformity of distribution of the lead.

clinging to the head, but the rotation is never fast enough to endangercentrifugal loss of lead. ihe apparatus employed for carrying out thesteps stated is susceptible of an almost uniimited range of variationsincluding apparatus for bodiiy moving the margins of the head2 and outof a circuiar molten bath pro or i ned to.

receive only the parts to be lead coated. ore. molten lead bathreceptacle mayxflbe provided having a'margin which the head 01, thefastener may overlie and along which the fastener be rolled with asector of the edge of the head submerged in the molten bath and thesector constantly advanced by the rolling movement of the head. Therolling operation is preferably continued beyond the bath, as bymovement along sarily somewhat idealized, the result'will be found to besubstantially uniform with a covering of lead or like soft metal fillingthe rabbet 4 and extending about the periphery and for a short distancebeneath the under surface of the head- 2, producing an encasing ring orgasket 6 possessing the peculiarity that it is not merely applied to orsuperimposed on the head I, but is actually integral with the head so asto be homogeneous withthe first coating and blended with the material ofthe fastener and form part of the head. it should also be understoodthat this sweating of the gasket 6 into integral relation with. the mainpart of the head 2 may be those above specifically stated, as bydie-stamping a cold gasket to the periphery of a previous= 1y properlyprepared fastenerhead, (say hot galvanized and supplied with a flux) andthen subjecting the parts'to electric current of sufil= cient amperageto produce the equit-alent of spot-welding. I

In Figure 3, the structure incorporates all of the features of Figure 2including .l

and head 2 with its enlargement 3 and rabbet l,

and having the ring or gasket 6 of lead or like soft metal encirclingthe periphery of. the head and filling the rabbet; and, in addition tothese details, the structure of Figure 3 provides for-an increase in thearea of the cushioning bearing against the sheet engaged by thefastener. To this end, the lead' is extended-inward'toward the body ifrom gasket 6'to fill the space 5 and to homogeneity. with the initialcoating and blended with the body I for a short distance of its length,

preferably brought to a cone frustum about body i, and thus providing atapering or curved fillet l. When theifastener l is driven through a"thus providing a filler for the space 5 which is sheet is. surrounded bya burr pressed to an outstanding position by themovement of the entering-endof body I through the. sheet, but usually and almost invariablythe surroundingmaterial of sheet "immediately contiguous to body andabove the burr is curved downward in blend= ing with the burr so as toproduce a hollow. cone fr'usturn of-relatively short length, and thecone frustum fillet r is prop rtioned to snuglyfill this hollow conicalspace of sheet I2. Whenthe fastener -l is a nail, and thenail' is drivento the position seen in Figure 3, the cushion or lead overlay 1 is notonly brought to-a snug relationship with respect to the sheet l2, but asthe sheet I l 2 is usually supported on a relatively rigid timber orother base, the resistance of the sheet to further movement of the nailinward under" a hammer blow will cause the metal to flow outward in alldirections toward the periphery of the head and thus to fill any slightirregularities at various points between the place of penetration ofsheet l2 and the outer periphery of the head.

The structure seen in Figure 3 may be produced in any of various ways,one inexpensive and acceptable mode consisting of first providing thehot galvanized or similar initial coat intermingled with the fiber ofthe fastener, then supplying a flux to the parts of the head and partsof body I to receive the lead, and then dipping the fastener (with thehead downward) into a molten bathof lead and lifting the fastener bodilyout of the bath, and then moving it laterally away from the bath whilewiping the then under face of the head, which is, of course, thehammerblow receiving face of the head. This wiping action is to removeexcess clinging lead so that no second coating or no appreciable portionof the second-applied coating will be left on the upper or hammer-blowreceiving surface of the head. The wiping action may be accomplishedin-any of various ways, such as by drawing the fastener while still inits inverted position across a travelling fabric belt movingsubstantially at right angles to the direction of the fastener in movingaway from the molten lead bath. It should be understood that referenceto lead, where specifically named herein, is intended to include anyappropriate soft metaladapted for the purposes for which the lead isused.

In Figure 4, the fastener is shown as a drive screw 8 having the headand peripheral flange ID on which is mounted the encircling covering orgasket ll corresponding to gasket 5 and likewise commingled or blendedwith the material of the head 9 and flange Ill. The same modes ofproduction as for Figure 2 may readily be employed for the securing ofthe results seen in Figure 4.

In Figure 5, the parts are identical with those seen in Figure 4 andproduced in the identical manner, except that the fastener 8 is anordinary wood screwor like high-pitched threaded fastener instead of adrive screw, so that the same reference numerals as employed in Figure4' have been applied to Figure 5, and the description of Figure 4 willequally apply.

In Figure 6, the structure and modes of production are identical withthose above described with respect to Figures 1 and 2, except that thehead is flat instead of concavo-convex or cupped so that no enclosedarea 5 appears, and, therefore, the appropriate reference numerals anddescription with respect to Figures 1 and 2 are em-- ployed regardingFigure 6. The flattened condition of the head 2, of course, is a matterof choice of design.

In use, when the fastener I is a nail, the nail is applied after themanner of any ordinary nail and driven into place until the coating orgasket 6 is firmly seated about the entire periphery of the head 2against the surface of the cover metal which it engages. The lead orother soft metal 6, as is well known, accommodates itself to anyirregularities, and, therefore, enables perfect contact with the engagedsurface of the cover metal, thus rendering the joint leak-proof. Themingled or blended character of the gasket 5 with respect to thematerial of the head 2 precludes loosening between the gasket and headeither under the force of hammer blows or under differential expansionincident to temperature variations with climatic changes. Also, the head2'is free to be struck by a hammer without any part of the 4 3 gasket 8directly receiving the blow. Thus, a

perfect leak-proof joint is produced in an easy,-

enables a wider bearing surface on the cover metal and thusproportionally enlarges themargin of safety against possibility ofdefective contact. But this is attained at the expense of the use of asubstantial additional amount of lead or like soft metal. In thisconnection it should be understood that the part 1 may be provided tofill the enclosing space 5 and be rendered homogeneous with the head 2without actually extending the material about the periphery of the headas seen at 6 in Figure 3, and in that event the structure will besubstantially that seen in Figure '7 which is otherwise identical withFigure 3 save the omission of the rabbet 4 and the fillet 1', so thatthe appropriate reference numerals from Figure 3 with the accompanyingdescription apply equally to the showing in Figure 7.

It should be understood that the several figures of the drawingillustrate what may be properly described as magnified embodiments overthose ordinarily or customarily employed in commerce, the enlargementbeing provided to facilitate clearness and accuracy of disclosure.

By virtue of the present invention a perfect joint is obtained free fromleakage while a saving of lead or like soft metal is effected up to ashigh as ninety per cent. over the previously proposed embodiments inwhich cast and.- diestamped lead coverings and lead .washers wereprovided. This saving is effected both because the lead is applied andlimited in quantity to the places only where it is required and noexcess lead is needed to guard against cracking or other separation andbecause the lead being homogeneous with the initial soft coating andtherewith or thereby commingled or blended with the balance of the headis needed in only a relatively thin layer as will become obvious when itis understood that thenailhead of a popular size of nail embodying thepresent invention will measure approximately one-half inch in diameter,whereas Figure 2 of the drawing showing such a nail is magnified tothree and one-half inches, or, in other words,

a the linear dimensions are increased seven-fold.

The coating or gasket 6 though ample for all commercial purposes will,when reduced from the enlargement shown in the drawing to its normaldimensions, be seen to involve a relatively small amount of lead.

The fastener is well adapted for practical ap-,

plication-exactly the same asany commercial fastener of similar typeexcept that the result will be a leak-proof joint without the expense,labor or uncertainty of the use of a lead head or a, lead washer. Theapplication may be effected by any of the known stresses, such as thetensioning of a wire if the fastener be a headed wire, or the driving ofa nail if the fastener be a nail, or the screw-driver rotation of ascrew if screw threads are employed, or the hammer driving of a drivescrewif thatbe the type of fastener. When a screw-driver is applied asto the embodiment seen in Figure 5, there is, of course,no possibledanger of injury to the lead, a thing that carmot be said where a leadcap or a lead washer is employed. When hammer driving is utilized, thehammer blows are received on the iron or other metal constituting theoriginal head of the fastener, and the impact of those blows does nottend to injure the integral lead gasket. Of course, initially appliedgalvanized coating is tity of lead required there is a proportionalsaving in the weight of the final fastener and this already known incommerce as capable ofwitlp standing hammer blows. I A further advantageof the present invention is the fact that in effecting a saving in thequanties ordinarily or customarily present tobe overcome. Not only so,but of course, the gasket or layer of'lead though somewhat idealized inthe showing in the drawing, may, of course, be va.-. ried in thicknessto any extent required according to the particular work in mind, andwhatever the thickness may be for such work, it will certainly be lessthan the thickness of a washer or die-stamped head applied to a fastenerfor the same purpose and will invariably-possess the immeasurablyvaluable capacity to effectively function while resisting anypossibility of leakage between the fastener proper and the lead coatingor gasket and resisting possibility of dam'age of the bond between thelead and the other metal of the fastener.

The terms blended, mixed, mingled and commingled are used throughoutthis specification and appended claims as substantially synonymous, and.refer to that state of the metal where at least an interlocking hasoccurred between two metals, as by the flowing of one in a. molten stateinto the pores of another and bonding in the interstices of such other.

What is claimed is:

l. The art of producing a metal fastener comprising forming a fastenerwith a head having a rabbet extending about its periphery and applying asoft metal cushion to the fastener including the rabbet and renderingthe material of the cushion commingled withthe material head of thefastener including that forming the rabbet.

2. The combination with the head of a fastener, of a cushioning gasketsweated to a condition intermingled with the material of the said head,the gasket being limited to the peripheral portions of the head and thehead being formed with a peripheral rabbet in which a portion of. thegasket is seated.

3. In the art of constructing fasteners, hot

, galvanizing a fastener and thus forming a soft 2. am a a coating onthe fastener with material or the coating commingled with material ofthe fastener, supplying a portion of the fastener with a flux.

dipping that portion of the head of the fastener having the flux supplyinto a molten soft metal bath until the soft metal becomes homogeneouswith the galvanized coating of the'fastener, and removing excess softmetal; a j

4. The art of constructing fasteners comprising dipping a portion of aheated fastener, while hot and galvanized, in a molten bath of leaduntil a coat is formed thereon commingled with the material ofthefastener, removing the fastener from the lead bath and removingexcess lead from the fastener. I

5 In the art of constructing fasteners, coating portions of the head ofthe fastener with a covering of metal applied in a manner to penetratethe pores of th fastener head and become commingled with the penetratedmaterial of the fastener, supplying the thus coated portions with flux,dipping the portions supplied with flux in a molten lead bath at atemperature suillcient to cause the lead to form a coating homogeneoustherewith, draining the excess molten lead from the fastener, andrevolving the fastener while draining.

6. In'the art of constructing fasteners, coating portions of the head ofthe fastener with a covering of metal applied in a manner to penetratethe pores of the fastener head, supplying theithus coated portions withflux, dipping the portions supplied with flux in a molten lead bath at atemperature sufllcient to cause the lead to form a coating on the firstcoating homogeneous therewith, and wiping excess molten lead from the'::

fastener.

7. The method of applying and .tenaciously bonding a lead enlargement tothe head of a.

metallic fastener which comprises galvanizing the fastener to bondthereto a coating having an afllnity for lead, and building the completelead enlargement on the coated fastener solely by placing the coatedfastener in contact with molten leadto cause an intimate bondto beformed between the fastener and the enlargement dependent uponv theaffinity of the lead and the coating. 1

8. The method of applying and tenaciously bonding a lead enlargement tothe head of a. metallic fastener which comprises providing the fastenerwith an intimately bonded coatingyomposed of a material haying anafilnity for lead, and building the complete lead enlargement on thecoating solely by contact of the coated fastener with molten lead tocause the enlargement to be intimately bonded to the coating solely bythe afllnity of the lead for the coating.

HEYMAN ROSENBERG.

